Stress just may be the #1 killer of frogs in Captivity. Parasites and Disease gain footholds and cause mortality based on stress present in the animal. Overall health declines rapidly in proportion to stress.
Even a 'happily mated' pair of frogs will endure stress. Stress is part of everyday life for these animals. As long as they come in contact with each other = stress. Mating = Stress. Just because your pair of frogs is laying eggs, doesn't mean they are living a happy carefree existence.
Although this genus of frogs is often found in high densities, this does not equate to being able to stuff them into 10 gallon sized enclosures. In situ, they have a myriad of places to flee, retreat and hide. Most people's vivariums, especially new hobbyists' are VERY BARE.
Let's just take an arbitrary number of possible hides, retreats and visual barriers available in their native environment....say, 12. 12 different options are quickly and easily available. How many can be replicated in a 10 gallon, which is actually more like a 7 gallon, when hardscaped...? Nowhere near 12. Probably nowhere near 6. Most likely 1 or 2.
Combating (wrestling in our hobby, as frogs do not have teeth and claws) is necessary for good reproductive health. As far as I am aware it is more of a reptilian reproductive issue than an amphibian. Male turtles combating come to mind. I think I read a paper that stated combating did not occur or NEED to occur in frogs for reproductive effectiveness. Ed or Roman could def chime in here on this issue.
My opinion? If you see 'wrasslin' once or twice , you can be sure it's happening @ ten times as much - that you don't see. It's not nessa for the frogs and is Always a stressor that needs to be addressed as per the individual keeper (owner) and his or her abilities and needs.